Thanks for the note...just looking at the pic of the replacement part, it appears that the valve can be dissasembled, the "stuck" core removed, and the replacement inserted...how much of a job is that? I'm fairly handly with tools.
It is worth a try to disassemble the current valve and just clean it up, possibly restoring function?
...a man's gotta understand
83 300D 360 K (Big Blue)
85 300CD 250 K (Little Blue)